It is known to pre-construct housing or commercial building units at a base yard and subsequently transport them, either whole or in two or more modules, to a client's allotment. Such buildings are typically referred to as manufactured or pre-built housing and for reference purposes will subsequently be referred to as manufactured housing.
A principal constraint in the design of manufactured housing is the strict dimensional limit set by road transport authorities for ordinary unescorted loads. For example, while it is possible to transport new manufactured homes in Australia having a width of 5 m, and a maximum height of 4.8 m, this typically requires expensive permits, escorts and set routes, and regulations confine travel times to daylight hours. In Australia and most countries, permits, escorts and/or set routes, and restrictions on time of travel, can be avoided only if the width load dimension is limited to 2.5 m and the height load dimension is limited to 4.8 m, less the height of a truck tray, which is normally 1.0 m.
If the manufactured housing is required to be transported overseas, it must comply with International Shipping Organisation (ISO) width dimensional limitations, which are more restrictive than the above referenced domestic limitations. Thus, in Australia, manufactured housing is such that the buildings or modules either require over-dimensional permits and escorts, or are severely restricted in their design and size by the width dimensional limits. Export housing, if attempted, is restricted by the ISO dimensional limitations.
Aside from the issue of additional cost, access of over-dimensional buildings to building sites is more restricted. For example, over-dimensional buildings are typically not suitable for dual occupancy sites, provision of granny flats or house extensions, if the permanent location of the over-dimensional building is not easily accessible due to access width restrictions. Further, over-dimensional buildings are not generally suitable for individual on-site housing, holiday housing, permanent housing such as country, coastal and suburban retirement villages or mining town accommodation.
Whether manufactured housing is designed beyond or within the transport dimensional limits, a variety of design approaches and features have been proposed to enhance the subsequent erected building while minimising its dimensions during transit.
For example, Australian patent application 16482/95, Australian patent 539799 and UK patent application 2257170 disclose manufactured housing with hinged or extendible roof, verandah or alcove elements. Australian patent application 71019/87 discloses a demountable building assembly which is adaptable to form one or more transportable containers. Building panels are stored in the containers. U.S. Pat. No. 4,635,412 discloses an assembly which folds to shipping container dimensions and includes multiple hinged panels to form, for example, an enlarged floor area. Extension floor panels hinge down on each side of the assembly and frame assemblies in turn hinge up from the outer edges of the extension floor panels. U.S. Pat. No. 5,237,784 discloses a transportable container which has the form of a shipping container and includes foldable walls which are designed to form an enlarged floor and ceiling. Australian patent 720059 discloses an arrangement in which a core of the house is transportable as a shipping container.
There is also manufactured housing that utilises shipping containers. U.S. Pat. No. 4,891,919 discloses a shipping container having hinge-down extension floor panels and hinge-up outer side walls that are designed to unfold to form a house. International patent publication WO 93/20297 discloses a shipping container that forms a central zone of a house. Further zones are formed by hinging out extension floors and roof extensions, and hinging up outer side walls.
Housing using a standard shipping container dimension of 2.1 m ceiling height cannot be approved due to building regulation requirements for a minimum or average ceiling height of 2.4 m in all habitable rooms other than wet areas.
Transportable housing is also provided in the form of kit housing. Like manufactured housing, some kit housing utilises shipping containers, while other kit housing utilises purpose-built structures which typically have the dimensions of shipping containers. U.S. Pat. No. 5,447,000 discloses an open frame which mimics a shipping container. The open frame structure can be incorporated into a subsequent house or dismantled to provide building components for the subsequent house.
While kit housing is usually cheaper to purchase, considerable time and greater effort and expertise is typically required to erect a house using kit housing compared with manufactured housing. Every component must be coded, often in several languages, in an elaborate kit manual adding to the complexity and difficulty of construction relative to manufactured housing. Manufactured housing is therefore more suitable for locations where building expenses are high, services such as power or accommodation are non-existent, or building expertise is limited. Furthermore, while warranties to protect the purchaser are required by law in Australia and other countries such as USA, United Kingdom and Canada for standard and manufactured housing, they are not possible for kit housing, leaving the buyer with no comeback or guarantee. A guarantee is required by lending authorities, and therefore kit housing is difficult to fund with loan money.
It is an object of the invention to provide improved manufactured housing that is of optimum dimensions during transport but enhanced size and form on erection. It is also preferable that erection be achievable easily and quickly.